Orientations of planar cataclasite zones in the Chicxulub peak ring as a ground truth for peak ring formation models

Hypervelocity impact cratering is an important geologic process but the rarity of large terrestrial craters on Earth and limited technical options to study processes in laboratory hinders our understanding large-scale processes. Drill core recovered from peak ring Chicxulub crater during International Ocean Discovery Program (IODP)/International Continental scientific Drilling (ICDP) Expedition 364 provides opportunity examine target rock deformation thus, assess models this regard. Using oriented computer tomography (CT) scans line scan images core, we present orientations mm-to-cm-scale planar cataclasite ultracataclasite zones deformed granitoid ring. In upper 470 m rock, dip towards center, whereas directions for are approximately tangential These two consistent with expected hydrocode-modeled principal stress outward movement rocks as transient develops, inward associated collapse crater. Near base a 96 m-thick interval highly-deformed melt fragments not observed elsewhere core; has previously been interpreted imbricate thrust zone within The below have different than those block above. This observation implies differential rotation overlying final stages peak-ring formation. Our results support acoustic fluidization process, wherein blocks that vibrate or slide relative each other allow flow collapse, size coherent increases over course modification regains its cohesive strength decreases.